In general, the electric field exerted by a charged body on a test charge is equal to the F on the test charge divided by the test charge,
Electric fields as vector quantities have both magnitudes and directions. By arbitrary assignments, the directions of field lines always travel toward negatively charged objects and away from positively charged objects. In other words, the field lines show how a positive test charge would move if placed in the field. The electric force is always tangent to the electric field . At any point in the system, the electric field present is the vector sum of all of the individual fields generated in the system.
